public class Circle {
    public int r;
    public double S;
    public double C;

    public int getR() {
        return r;
    }
    public void ComMeth(){
        S = 3.14 * r * r;
        C = 2 * 3.14 * r;
        System.out.println("这个圆的半径为" + r + "，面积为" + S + "，周长为" + C);
    }

    public static void main(String[] args) {
        Circle circle = new Circle();
        circle.r = 4;
        circle.ComMeth();
    }
}
